Cytokeratin phenotypes at the dento-gingival junction in relative health and inflammation, in smokers and nonsmokers.
OBJECTIVE
The cells of the junctional epithelium (JE) provide and maintain the epithelial attachment, and remain morphologically and phenotypically distinct from oral sulcular (OSE) and external oral epithelia (EOE), from which they may be regenerated de novo. Expression of cytokeratins (CK) in human epithelia has been shown to be highly site-specific, implying a functional role. The aims of this study were to differentiate between the cytokeratin profiles of JE, OSE, EOE and pocket epithelia (PE) in health and disease, in smokers and non-smokers.


METHODS
The cytokeratin profiles of 40 samples of healthy and clinically inflamed human gingival tissue taken from 15 smokers and 25 non-smokers were studied by immunocytochemistry. Cryostat sections of fresh frozen gingival tissues were stained with a panel of monoclonal antibodies (mAb) and visualised by a biotin-Streptavidin-peroxidase complex technique.


RESULTS
JE and PE expressed an identical range of cytokeratins irrespective of the inflammatory or smoking status, with the exception of CK4 expression, which tended to be increased in smokers. The OSE and EOE expressed non-cornifying and cornifying differentiation cytokeratins respectively, but in the presence of inflammation, both these epithelia showed increased expression of CK19 at a basal level in association with expression of one or more of the simple cytokeratins. JE/PE expressed CK17 in external layers only, approximating the tooth surface. All epithelia expressed CK6, 16 the markers of high cell turnover.


CONCLUSIONS
CK 19 was a consistent differentiation marker for JE and PE. Expression of CK8, 18 was enhanced by inflammation. CK4 expression increased in association with smoking. Markers of differentiation were not always co-expressed equally within a pair. Pairs were not always completely mutually exclusive with frequent co-localisation.
Pritlove-Carson
S
S
Department of Periodontology, United Medical School of Guy's, London, UK.
Charlesworth
S
S
Morgan
P R
PR
Palmer
R M
RM
D000293:Adolescent; D000328:Adult; D015415:Biomarkers; D002454:Cell Differentiation; D002648:Child; D003238:Connective Tissue / Q000378:metabolism; D004846:Epithelial Attachment / Q000378:metabolism* / Q000473:pathology; D004848:Epithelium / Q000378:metabolism; D005260:Female; D005881:Gingiva / Q000166:cytology / Q000378:metabolism*; D005891:Gingivitis / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D007633:Keratins / Q000032:analysis / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010514:Periodontal Pocket / Q000378:metabolism* / Q000473:pathology; D010641:Phenotype; D012907:Smoking / Q000009:adverse effects / Q000378:metabolism
D015415:Biomarkers; D007633:Keratins